Tool Filter MCP

import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'; import { ListToolsRequestSchema, CallToolRequestSchema, Tool, } from '@modelcontextprotocol/sdk/types.js'; import { ProxyOrchestrator } from './proxy.js'; import { readFileSync } from 'fs'; import { fileURLToPath } from 'url'; import { dirname, join } from 'path'; const __dirname = dirname(fileURLToPath(import.meta.url)); const packageJson = JSON.parse( readFileSync(join(__dirname, '..', 'package.json'), 'utf-8') ); const VERSION = packageJson.version; export class MCPServer { private proxy: ProxyOrchestrator; constructor(proxy: ProxyOrchestrator) { this.proxy = proxy; } async handleListTools(): Promise<{ tools: Tool[] }> { const tools = this.proxy.getCachedTools(); return { tools: tools.map( (t): Tool => ({ name: t.name, description: t.description, inputSchema: { type: 'object', ...t.inputSchema, }, }) ), }; } async handleCallTool( name: string, args: Record<string, unknown> ): Promise<{ content?: unknown[]; isError?: boolean }> { if (!this.proxy.isToolAllowed(name)) { throw { code: -32601, message: `Tool not found: ${name}`, }; } const connection = this.proxy.getUpstreamConnection(); const result = await connection.callTool(name, args || {}); return result as { content?: unknown[]; isError?: boolean }; } supportsResources(): boolean { return true; } supportsPrompts(): boolean { return true; } } export async function createMCPServer(proxy: ProxyOrchestrator): Promise<Server> { const server = new Server( { name: 'tool-filter-mcp', version: VERSION, }, { capabilities: { tools: {}, }, } ); server.setRequestHandler(ListToolsRequestSchema, async () => { const tools = proxy.getCachedTools(); return { tools: tools.map( (t): Tool => ({ name: t.name, description: t.description, inputSchema: { type: 'object', ...t.inputSchema, }, }) ), }; }); server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: args } = request.params; if (!proxy.isToolAllowed(name)) { throw { code: -32601, message: `Tool not found: ${name}`, }; } const connection = proxy.getUpstreamConnection(); const result = await connection.callTool(name, args || {}); return result as { content?: unknown[]; isError?: boolean }; }); const transport = new StdioServerTransport(); await server.connect(transport); return server; }